1. Technical Field
The present disclosure relates to an electrosurgical system and method for performing electrosurgical procedures. More particularly, the present disclosure relates to a system and method for transmitting and monitoring tissue and energy parameter information at the treatment site using sensor signal feedback from the treatment site. The present disclosure also relates to a system and method for transmitting, monitoring, and controlling electrosurgical radio frequency energy in a closed loop manner based on the tissue and energy parameters.
2. Background of Related Art
Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, or coagulate tissue. In bipolar electrosurgery, one of the electrodes of the hand-held instrument functions as the active electrode and the other as the return electrode. The return electrode is placed in close proximity to the active electrode such that an electrical circuit is formed between the two electrodes (e.g., electrosurgical forceps). In this manner, the applied electrical current is limited to the body tissue positioned between the electrodes. When the electrodes are sufficiently separated from one another, the electrical circuit is open and thus inadvertent contact of body tissue with either of the separated electrodes prevents current flow.
Bipolar electrosurgery generally involves the use of forceps. A forceps is a pliers-like instrument which relies on mechanical action between its jaws to grasp, clamp and constrict vessels or tissue. So-called “open forceps” are commonly used in open surgical procedures whereas “endoscopic forceps” or “laparoscopic forceps” are, as the name implies, used for less invasive endoscopic surgical procedures. Electrosurgical forceps (open or endoscopic) utilize mechanical clamping action and electrical energy to effect hemostasis on the clamped tissue. The forceps include electrosurgical conductive surfaces which apply the electrosurgical energy to the clamped tissue. By controlling the intensity, frequency and duration of the electrosurgical energy applied through the conductive plates to the tissue, the surgeon can coagulate, cauterize and/or seal tissue.
Tissue or vessel sealing is a process of liquefying the collagen, elastin and ground substances in the tissue so that they reform into a fused mass with significantly-reduced demarcation between the opposing tissue structures. Cauterization involves the use of heat to destroy tissue and coagulation is a process of desiccating tissue wherein the tissue cells are ruptured and dried.
Tissue sealing procedures involve more than simply cauterizing or coagulating tissue to create an effective seal; the procedures involve precise control of a variety of factors. For example, in order to affect a proper seal in vessels or tissue, it has been determined that two predominant mechanical parameters must be accurately controlled: the pressure applied to the tissue; and the gap distance between the electrodes (i.e., distance between opposing jaw members or opposing sealing surfaces). In addition, electrosurgical energy must be applied to the tissue under controlled conditions to ensure creation of an effective vessel seal.
Transmission of electrosurgical energy to the treatment site, namely from the electrosurgical generator to the instrument, is accomplished via an electrosurgical cable. During transmission an electrical field is generated through the cable and stray electrosurgical RF energy is typically emitted along the cable path, which tends to reduce treatment energy and generates RF noise. Moreover, the electrical fields may interfere with the operation of other electronic equipment in the surgical area, such as patient monitoring equipment.